Nolan Arenado and Carlos Gonzalez hit back-to-back homers in the first inning, and the Giants couldn't respond against the sharp pitching of Jorge De La Rosa in a 2-1 loss to the Colorado Rockies on Friday night. Two of the strikeouts came in the sixth inning, helping him get out of a jam and he induced an inning-ending double play grounder from Juan Perez after giving up a one-out single to Kelby Tomlinson in the seventh. Rookie Chris Heston (11-9) went 5 2-3 innings for the Giants and allowed seven hits and two runs, both on the solo homers in the first. Matt Duffy singled and Buster Posey was hit by a pitch around a strikeout by Brandon Belt to load the bases. Utility player Matt McBride was designated for assignment to clear a spot on the 40-man roster for Justin Morneau, who was activated Friday after missing nearly four months because of a concussion. Rockies: RHP Chad Bettis (6-4) is 1-0 with a 4.09 ERA in two starts since returning from a six-week stint on the DL due to inflammation in his pitching elbow.